Rockwool or glass wool mats are often employed to-day for insulating buildings, houses and other structures. Both of these types of insulating mats are encumbered with environmental disadvantages.
Glass wool, e.g., is manufactured by melting standard glass to which is added some additives which give the glass a low level of thermal conductivity, whereupon the glass is drawn out by means of rapidly rotating winding machines into long thin threads. The threads are collected and bonded by means of a phenolic adhesive into, e.g., insulating mats of varying thickness and rigidity. Rockwool is produced in an analogous manner, but here it is rocks which are melted, lime is added and drawn out in rapidly rotating winding machines. In this case too a phenolic adhesive is employed to form insulating mats. Both of these processes require high temperatures of many hundreds of degrees Celsius, and thereby a relatively high energy consumption, and they use non-renewable resources such as rock and sand respectively.
A known problem in the building industry is that both types of insulating mats can cause allergic reactions such as itching, smarting and sore throats, particularly while working on laying the mats. In addition, the fibres are hard and will penetrate the skin to a certain extent, thus producing mats which are prickly and cause discomfort to bare skin. These fibre needles can cause a great deal of irritation as well as being difficult to remove from the skin. It is therefore necessary to use respiratory protection and fabrics which provide complete cover while working with insulating mats. This makes the building process both more complicated and more expensive.
Another problem is that after a time the adhesive will become dry and crumble up, with the result that rock or glass fibre in the insulating material will work loose. Thus in many cases fibre will seep into the building through cracks etc., impairing the quality of the indoor air. Several cases are known where an unacceptably high level of glass fibre and/or rockwool fibre has been found in the filters of the ventilation systems of, e.g., primary schools. There is now a suspicion that glass fibre may have a carcinogenic effect. Another consequence of the atomisation of the adhesive is that after a time the insulating mats will sag, thus impairing the insulating material's insulating power. This is detrimental from an environmental point of view since it results in the mats being unsuitable for recycling, and since a reduction in the insulation of the buildings results in increased energy consumption for heating.
There is therefore a need for new types of insulating materials which can solve the above-mentioned problems, and which are environmentally friendly both with regard to people and the environment in general.